Heritability Analysis in Twins Indicates a Genetic Basis for Velopharyngeal Morphology

2021 ◽  
pp. 105566562110455
Author(s):  
Myoung Keun Lee ◽  
Chenxing Liu ◽  
Elizabeth J. Leslie ◽  
John R. Shaffer ◽  
Jamie L. Perry ◽  
...  
Keyword(s):  
Structural Equation ◽  
Genetic Basis ◽  
Genetic Factors ◽  
Genetic Correlations ◽  
Muscle Length ◽  
Equation Modeling ◽  
Normal Range ◽  
Heritability Analysis ◽  
Velopharyngeal Function ◽  
Normal Speech

The velopharyngeal mechanism is comprised of several muscular components that act in a coordinated manner to control airflow through the nose and mouth. Proper velopharyngeal function is essential for normal speech, swallowing, and breathing. The genetic basis of normal-range velopharyngeal morphology is poorly understood. The purpose of this study was to estimate the heritability of velopharyngeal dimensions. We measured five velopharyngeal variables (velar length, velar thickness, effective velar length, levator muscle length and pharyngeal depth) from MRIs of 155 monozygotic and 208 dizygotic twin pairs and then calculated heritability for these traits using a structural equation modeling approach. The heritability estimates were statistically significant (95% confidence intervals excluded zero) and ranged from 0.19 to 0.46. There was also evidence of significant genetic correlations between pairs of traits, pointing to the influence of common genetic effects. These results indicate that genetic factors influence variation in clinically relevant velopharyngeal structures.

scholarly journals Variation and Heritability in Hair Diameter and Curvature in an Australian Twin Sample

2016 ◽  
Vol 19 (4) ◽  
pp. 351-358 ◽  
Author(s):  
Yvonne Y. W. Ho ◽  
Mark Brims ◽  
Dennis McNevin ◽  
Timothy D. Spector ◽  
Nicholas G. Martin ◽  
...  
Keyword(s):  
Structural Equation ◽  
Genetic Factors ◽  
Fiber Diameter ◽  
Scalp Hair ◽  
Genetic Correlations ◽  
Equation Modeling ◽  
Environmental Correlations ◽  
Sex Limitation ◽  
Objectively Measured ◽  
Hair Diameter

Hair diameter and curvature are two characteristics of human scalp hair used in forensic contexts. While previous data show that subjective categorization of hair curvature is highly heritable, the heritability of objectively measured curvature and diameter, and variability of hair characteristics within each individual have not yet been studied. The present study measured hair diameter and curvature using an optical fiber diameter analyzer in a sample of 2,332 twins and siblings. Heritability was estimated using maximum likelihood structural equation modeling. Results show sex differences in the magnitude of genetic influence for mean diameter and curvature, with the vast majority of the variance accounted for by genetic effects in males (diameter = 86%, curvature = 53%) and females (diameter = 77%, curvature = 61%). The consistency of diameter (variance within an individual) was also highly heritable, but did not show sex limitation, with 68% of the variance accounted for by genetic factors. Moderate phenotypic correlations were seen between diameter and consistency (r = 0.3) but there was little correlation between diameter and curvature (r = -0.13). A bivariate Cholesky analysis was used to estimate the genetic and environmental correlations between hair diameter and consistency, yielding genetic correlations of rgF = 0.27 for females and rgM = 0.25 for males.

scholarly journals Genetic Influences on Individual Differences in Exercise Behavior during Adolescence

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Niels van der Aa ◽  
Eco J. C. De Geus ◽  
Toos C. E. M. van Beijsterveldt ◽  
Dorret I. Boomsma ◽  
Meike Bartels
Keyword(s):  
Structural Equation ◽  
Leisure Time ◽  
Genetic Factors ◽  
Threshold Model ◽  
Exercise Behavior ◽  
Equation Modeling ◽  
Substantial Part ◽  
Vigorous Exercise ◽  
Exercise Frequency ◽  
Age Cohorts

The aim of this study was to investigate the degree to which genetic and environmental influences affect variation in adolescent exercise behavior. Data on regular leisure time exercise activities were analyzed in 8,355 adolescent twins, from three-age cohorts (13-14, 15-16, and 17–19 years). Exercise behavior was assessed with survey items about type of regular leisure time exercise, frequency, and duration of the activities. Participants were classified as sedentary, regular exercisers, or vigorous exercisers. The prevalence of moderate exercise behavior declined from age 13 to 19 years with a parallel increase in prevalence of sedentary behavior, whereas the prevalence of vigorous exercise behavior remained constant across age cohorts. Variation in exercise behavior was analyzed with genetic structural equation modeling employing a liability threshold model. Variation was largely accounted for by genetic factors (72% to 85% of the variance was explained by genetic factors), whereas shared environmental factors only accounted for a substantial part of the variation in girls aged 13-14 years (46%). We hypothesize that genetic effects on exercise ability may explain the high heritability of exercise behavior in this phase of life.

Distribution and Heritability of Recurrent Ear Infections

1997 ◽  
Vol 106 (8) ◽  
pp. 624-632 ◽  
Author(s):  
Kari J. Kvaerner ◽  
Jennifer R. Harris ◽  
Kristian Tambs ◽  
Per Magnus
Keyword(s):  
Structural Equation ◽  
Genetic Factors ◽  
Age Of Onset ◽  
Population Based ◽  
Equation Modeling ◽  
Relative Contribution ◽  
Genes And Environment ◽  
Ear Infections ◽  
The Mean ◽  
Familial Environment

The distribution of recurrent ear infections was obtained from a population-based sample of 2,750 pairs of Norwegian twins born between 1967 and 1974. The lifetime prevalence of self-reported recurrent ear infections was 8.9%, with a significant predominance of female cases. The mean age of onset was 4.2 years, with a gradual decrease in occurrence from 2 to 7 years of age. Among monozygotic pairs, the rate of tetrachoric correlation between co-twins was almost identical in males (0.73, SE 0.08) and females (0.74, SE 0.06), but among the dizygotic pairs the correlation was clearly higher in males (0.53, SE 0.12) than in females (0.20, SE 0.12). The value in the unlike-sexed dizygotic twins (0.25, SE 0.05) was intermediate to that of the like-sexed male and female dizygotic pairs. The relative contribution of genes and environment to variability in the predisposition to develop otitis media was estimated by means of structural equation modeling. Variation in liability to ear infections was mainly explained by additive genetic and dominance factors in females, for whom heritability was estimated at 74%. The remaining 26% of the variation in liability was explained by individual environmental factors. In males, 45% of the variation could be accounted for by genetic factors, 29% by common familial environment, and the remaining 26% by individual environmental effects.

scholarly journals The Relationship Between Neuroticism and Inflammatory Markers: A Twin Study

2014 ◽  
Vol 17 (3) ◽  
pp. 177-182 ◽  
Author(s):  
Arthur A. Sas ◽  
Frühling V. Rijsdijk ◽  
Johan Ormel ◽  
Harold Snieder ◽  
Harriëtte Riese
Keyword(s):  
Inflammatory Markers ◽  
Structural Equation ◽  
Inflammatory Marker ◽  
Genetic Correlations ◽  
Equation Modeling ◽  
Reactive Protein ◽  
Inflammatory Status ◽  
Physical Disorders ◽  
The Relationship ◽  
Important Marker

Introduction: Neuroticism is an important marker of vulnerability for both mental and physical disorders. Its link with multiple etiological pathways has been studied before. Inflammatory markers have been demonstrated to predict similar mental and physical disorders as neuroticism. However, currently no study has focused on the shared genetic background of neuroticism and inflammatory markers. In the present study we will focus on the phenotypic and genetic relationship between neuroticism and three commonly used inflammatory markers: C-reactive protein (CRP), fibrinogen and Immunoglobulin-G (IgG). Material and Methods: The study was conducted in 125 Dutch female twin pairs. For each participant, four different neuroticism scores were available to calculate a neuroticism composite score that was used in the statistical analyses. Blood samples for inflammatory marker determination were taken after an overnight fast. Heritabilities, phenotypic and genetic correlations were estimated using bivariate structural equation modeling. Results: Heritabilities are fair for neuroticism (0.55), CRP (0.52) and fibrinogen (0.67) and moderate for IgG (0.43). No significant phenotypic or genetic correlations were found between neuroticism and the inflammatory markers. Interaction models yielded no moderation of the genetic and environmental pathways in the regulation of inflammatory markers by neuroticism. Conclusion: Substantial heritabilities were observed for all variables. No evidence was found for significant shared (or moderation of) genetic or environmental pathways underlying neuroticism and inflammatory status.

Genetic and Environmental Influences on the Handedness and Footedness in Japanese Twin Children

2005 ◽  
Vol 8 (6) ◽  
pp. 649-656 ◽  
Author(s):  
Syuichi Ooki
Keyword(s):  
Environmental Factors ◽  
Secondary School ◽  
Structural Equation ◽  
Genetic Factors ◽  
Genetic Effect ◽  
Model Fit ◽  
Equation Modeling ◽  
Genetic Contribution ◽  
Japanese Education ◽  
Twin Children

AbstractThe purpose of this study was to examine the genetic contribution to handedness and footedness in childhood using one of the largest available databases of Japanese twins. The participants were 1131 twin pairs, 1057 males and 1205 females, of 11 or 12 years of age (6th grade of secondary school in the Japanese education system). All data were gathered by questionnaire. The prevalence of left (nonright) handedness was 15% in males and 13% in females. The prevalence of left (nonright) footedness was 13% in males and 11% in females. The similarities between twin pairs, estimated by concordance rates and tetrachoric correlations, suggested a slight genetic effect on male handedness, no genetic effect on female handedness, and no genetic effect on footedness in either sex. Structural equation modeling showed small genetic factors (11%) in male handedness and no genetic factors in female handedness. As to footedness, no genetic factors were observed in either sex. The effects of nonshared environmental factors were large (85%) in males and moderate (44%) in females. Moreover, handedness and footedness tended to be concordant irrespective of sex, with polychoric correlations over r = .70. The results of bivariate genetic analyses were not necessarily satisfactory. For males, no model fit. For females, shared and nonshared environmental factors explained the concordance of handedness and footedness. It was concluded that the genetic effects on handedness and footedness are relatively small, as is their association; moreover, considerably large twin samples are needed to obtain stable and appropriate results.

Genetic and environmental determination of tracking in static strength during adolescence

2005 ◽  
Vol 99 (4) ◽  
pp. 1317-1326 ◽  
Author(s):  
Maarten W. Peeters ◽  
Martine A. Thomis ◽  
Hermine H. M. Maes ◽  
Gaston P. Beunen ◽  
Ruth J. F. Loos ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Structural Equation ◽  
Genetic Factors ◽  
Peak Height ◽  
Static Strength ◽  
Height Velocity ◽  
Equation Modeling ◽  
Growth Spurt ◽  
Peak Height Velocity ◽  
Measurement Occasion

The purpose of this study was to determine whether the observed phenotypic stability in static strength during adolescence, as measured by interage correlations in arm pull, is mainly caused by genetic and/or environmental factors. Subjects were from the Leuven Longitudinal Twin Study ( n = 105 pairs, equally divided over 5 zygosity groups). Arm-pull data were aligned on age at peak height velocity to attenuate the temporal fluctuations in interage correlations caused by differences in timing of the adolescent growth spurt. Developmental genetic models were fitted using structural equation modeling. After the data were aligned on age at peak height velocity, the annual interage correlations conformed to a quasi-simplex structure over a 4-yr interval. The best-fitting models included additive genetic and unique environmental sources of variation. Additive genetic factors that already explained a significant amount of variation at previous measurement occasions explained 44.3 and 22.5% of the total variation at the last measurement occasion in boys and girls, respectively. Corresponding values for unique environmental sources of variance are 31.2 and 44.5%, respectively. In conclusion, the observed stability of static strength during adolescence is caused by both stable genetic influences and stable unique environmental influences in boys and girls. Additive genetic factors seem to be the most important source of stability in boys, whereas unique environmental factors appear to be more predominant in girls.

A twin study of genetic and environmental influences on tobacco initiation, regular tobacco use and nicotine dependence

2004 ◽  
Vol 34 (7) ◽  
pp. 1251-1261 ◽  
Author(s):  
HERMINE H. MAES ◽  
PATRICK F. SULLIVAN ◽  
CYNTHIA M. BULIK ◽  
MICHAEL C. NEALE ◽  
CAROL A. PRESCOTT ◽  
...  
Keyword(s):  
Nicotine Dependence ◽  
Tobacco Use ◽  
Structural Equation ◽  
Genetic Factors ◽  
Smoking Behavior ◽  
Twin Studies ◽  
Population Based ◽  
Equation Modeling ◽  
Opposite Sex ◽  
Tobacco Initiation

Background. Numerous twin studies have reported significant genetic contributions to the variability of tobacco initiation (TI), while fewer studies have shown similar results for the persistence of smoking behavior, or nicotine dependence (ND). As the development of ND requires regular tobacco use (RTU) which in turn requires TI, a conditional approach is necessary.Method. We used structural equation modeling of multi-step conditional processes to examine the relationship between genetic and environmental risk factors for TI, RTU and ND. The tobacco variables were assessed by personal interview in female, male and opposite-sex twin pairs from the population-based Virginia Twin Registry.Results. The results suggested that the liabilities to TI, RTU and ND were correlated. Over 80% of the variance in liability to TI and RTU were shared, and a smaller proportion was shared between RTU and ND. The heritabilities were estimated at 75%, 80% and 60% respectively for TI, RTU and ND. The variance specific to liability to RTU was entirely accounted for by additive genetic factors. Only a modest part of the heritability in liability of ND was due to genetic factors specific to ND. Shared environmental factors were not significant. No sex differences were found for the sources of variation or causal paths, but prevalences were significantly greater in males versus females.Conclusions. This study showed significant overlap in the contribution of genetic factors to individual differences in TI, RTU and ND. Furthermore, there was evidence for significant additional genetic factors specific to RTU and ND.

scholarly journals Heritability of Type 2 Diabetes in the Washington State Twin Registry

2019 ◽  
Vol 22 (2) ◽  
pp. 95-98 ◽  
Author(s):  
Ally R. Avery ◽  
Glen E. Duncan
Keyword(s):  
Type 2 Diabetes ◽  
Environmental Factors ◽  
Structural Equation ◽  
Genetic Factors ◽  
Washington State ◽  
Equation Modeling ◽  
Twin Registry ◽  
Genetic And Environmental Factors ◽  
Adult Twins

AbstractApproximately 12% of U.S. adults have type 2 diabetes (T2D). Diagnosed T2D is caused by a combination of genetic and environmental factors including age and lifestyle. In adults 45 years and older, the Discordant Twin (DISCOTWIN) consortium of twin registries from Europe and Australia showed a moderate-to-high contribution of genetic factors of T2D with a pooled heritability of 72%. The purpose of this study was to investigate the contributions of genetic and environmental factors of T2D in twins 45 years and older in a U.S. twin cohort (Washington State Twin Registry, WSTR) and compare the estimates to the DISCOTWIN consortium. We also compared these estimates with twins under the age of 45. Data were obtained from 2692 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs over 45 and 4217 twin pairs under 45 who responded to the question ‘Has a doctor ever diagnosed you with (type 2) diabetes?’ Twin similarity was analyzed using both tetrachoric correlations and structural equation modeling. Overall, 9.4% of MZ and 14.7% of DZ twins over the age of 45 were discordant for T2D in the WSTR, compared to 5.1% of MZ and 8% of DZ twins in the DISCOTWIN consortium. Unlike the DISCOTWIN consortium in which heritability was 72%, heritability was only 52% in the WSTR. In twins under the age of 45, heritability did not contribute to the variance in T2D. In a U.S. sample of adult twins, environmental factors appear to be increasingly important in the development of T2D.

scholarly journals Heritability of Gestational Weight Gain – A Swedish Register-Based Twin Study

2015 ◽  
Vol 18 (4) ◽  
pp. 410-418 ◽  
Author(s):  
Elina Scheers Andersson ◽  
Karri Silventoinen ◽  
Per Tynelius ◽  
Ellen A. Nohr ◽  
Thorkild I. A. Sørensen ◽  
...  
Keyword(s):  
Weight Gain ◽  
Environmental Factors ◽  
Gestational Weight Gain ◽  
Structural Equation ◽  
Genetic Factors ◽  
Complex Trait ◽  
Complete Data ◽  
Equation Modeling ◽  
Linkage Data ◽  
Gestational Weight

Gestational weight gain (GWG) is a complex trait involving intrauterine environmental, maternal environmental, and genetic factors. However, the extent to which these factors contribute to the total variation in GWG is unclear. We therefore examined the genetic and environmental influences on the variation in GWG in the first and second pregnancy in monozygotic (MZ) and dizygotic (DZ) twin mother-pairs. Further, we explored if any co-variance existed between factors influencing the variation in GWG of the mothers’ first and second pregnancies. By using Swedish nationwide record-linkage data, we identified 694 twin mother-pairs with complete data on their first pregnancy and 465 twin mother-pairs with complete data on their second pregnancy during 1982–2010. For a subanalysis, 143 twin mother-pairs had complete data on two consecutive pregnancies during the study period. We used structural equation modeling (SEM) to assess the contribution of genetic, shared, and unique environmental factors to the variation in GWG. A bivariate Cholesky decomposition model was used for the subanalysis. We found that genetic factors explained 43% (95% CI: 36–51%) of the variation in GWG in the first pregnancy and 26% (95% CI: 16–36%) in the second pregnancy. The remaining variance was explained by unique environmental factors. Both overlapping and distinct genetic and unique environmental factors influenced GWG in the first and the second pregnancy. This study showed that GWG has a moderate heritability, suggesting that a large part of the variation in the trait can be explained by unique environmental factors.

scholarly journals Genetic and Environmental Influences on Finger-Sucking and Nail-Biting in Japanese Twin Children

2005 ◽  
Vol 8 (4) ◽  
pp. 320-327 ◽  
Author(s):  
Syuichi Ooki
Keyword(s):  
Structural Equation ◽  
Genetic Factors ◽  
Equation Modeling ◽  
Phenotypic Variance ◽  
Medical Interview ◽  
Total Phenotypic Variance ◽  
Nail Biting ◽  
Males And Females ◽  
Twin Children ◽  
Variance Explained

AbstractThe purpose of this study was to clarify the genetic contribution to finger-sucking and nail- biting in childhood using the largest databases available on Japanese twins. The subjects were 1131 pairs of 12-year-old twin children, consisting of 1057 males and 1205 females. All data were gathered by maternal questionnaire, and responses to the questionnaire were checked in the medical interview. The prevalence of finger-sucking between 0 to 2 years was 40% in males and 43% in females (p = .0053). The prevalence of nail-biting up until the age of 12 years was 28% in males and 26% in females (nonsignificant). Concordance rates and polychoric correlations were all higher in monozygotic pairs than in dizygotic pairs, irrespective of the sex combination. Univariate and bivariate genetic analyses using structural equation modeling was performed. The results showed that the proportion of total phenotypic variance attributable to genetic influences was 66% in males and 50% in females for finger-sucking, and 50% in both males and females for nail-biting. A co-occurrence of finger-sucking and nail-biting was observed in 17.7% of males (tetrachoric correlation: r = .40) and 15.7% of females (r = .32), which was attributed partly to common genetic or environmental factors. The proportion of total shared variance explained by genetic factors was 67%.

Sign in / Sign up

Export Citation Format

Share Document